For the decontamination of chemically contaminated surfaces, it is necessary to spread on the surface chemical material which neutralizes the noxious effect of the contaminant. For example, where the noxious material is acidic the neutralizing agent will be basic, and vice versa; and there may be other forms of neutralization such as compounding the contaminants, e.g. in the case of elementary bromine, and the like. For the performance of such decontamination, it is customary to use a dispensing hopper which is continuously or intermittently charged with a ready-mixed aqueous dispersion of the decontaminating agent. At its lower part, the hopper comprises two horizontally aligned pipes axially spaced from each other, one serving for the injection of water and the other for the delivery of a liquid phase and which together form a pump which sucks the said aqueous dispersion suspension into the delivery pipe from which it is ejected. In the course of operation, the hopper is moved along and across the contaminated area with the object of spreading the decontaminating agent thereon.
Experience has shown that these known dispensers suffer from a fundamental defect in that the ready-made aqueous dispersion charged into the hopper tends to clog and block the region around the two aligned pipes and also the interior of the delivery pipe, with the result that after a relatively short while the dispenser no longer functions and has to be replaced for servicing. Apart from the operational inconvenience involved, this also prolongs significantly the decontamination operation, which is an obvious serious disadvantage.
It is therefore the object of the present invention to provide an improved dispenser apparatus for the decontamination of chemically contaminated surfaces.